The use of water separators in diesel engine fuel filters is a well-known expedient to rid the fuel of contaminants that might cause a malfunction of the engine. Many of these consist merely of a water drainage reservoir at the bottom of the fuel filter connected by a drain tube which expels the water to the ground. Concern over such cavalier discharge of contaminated fluids into the environment has led to the design of water separators that collect the separated water in a container located at the bottom of the filter assembly. Such containment of the separated water requires that the driver of the vehicle periodically empty the separated water from the container prior to the container becoming full. A problem arises, however, in that the driver cannot always be relied upon to remember to empty the separated water when required. To overcome this problem, some water separators contain sensors which are activated when the water reaches a predetermined level in the reservoir, thereby energizing a signal light located on the dashboard of the vehicle which warns the driver of the need to drain the filter. However, such signals still require that the driver stop the vehicle and manually empty the separated water from the filter unit. This represents a considerable inconvenience to the driver, and there is still no guarantee that the driver will not simply ignore the warning light on the dashboard.
A further problem with automotive fuel filters is that after a period of time, the filter element becomes clogged with the contaminants that have been filtered from the fuel and must be replaced. The fuel within the fuel filter canister is typically drained during the filter element replacement operation and manual printing of the fuel pump is thereafter required in order to restore the fuel system to a functional state. The need to prime the fuel pump after replacement of the fuel filter adds extra service time to the fuel filter replacement operation and is an inconvenience to the service technician.
There is therefore a need for a fuel system that provides for an automatic draining of water separated from the fuel in the fuel filter when such separated water reaches a predetermined level. There is also a need for a fuel system that allows for semi-automatic printing of the fuel pump after the fuel filter element has been replaced. The present invention is directed toward meeting these needs.